Add test for clean shutdown

Makefile

@@ -275,6 +275,7 @@ rust-test-intensive:
 	QUICKCHECK_TESTS=100000000 make rust-test
 
 api-tests: all-debug
+	./tests/api/clean-shutdown.js
 	./tests/api/state.js
 
 covreport:

tests/api/clean-shutdown.js

@@ -0,0 +1,31 @@
+#!/usr/bin/env node
+"use strict";
+
+// This test checks that calling emulator.stop() will remove all event
+// listeners, so that the nodejs process cleanly and automatically exits.
+
+const fs = require("fs");
+const V86 = require("../../build/libv86-debug.js").V86;
+
+process.on("unhandledRejection", exn => { throw exn; });
+
+const config = {
+    bios: { url: __dirname + "/../../bios/seabios.bin" },
+    vga_bios: { url: __dirname + "/../../bios/vgabios.bin" },
+    cdrom: { url: __dirname + "/../../images/linux3.iso", async: true },
+    network_relay_url: "<UNUSED>",
+    autostart: true,
+    memory_size: 32 * 1024 * 1024,
+    filesystem: {},
+    log_level: 0,
+    screen_dummy: true,
+};
+
+const emulator = new V86(config);
+
+setTimeout(function()
+    {
+        console.error("Calling stop()");
+        emulator.stop();
+        console.error("Called stop()");
+    }, 3000);